So many lines - you normally read them from a file!
Then instead of
You save the memory with
and in this case even save the loop with
All these snippets may be pretty memory-intensive. In all these cases, the file-handle is being read in list context. So, you'd end up consuming (and storing in memory) the file data all at once.
As balajesuri has already pointed out, reading the handle in scalar context would be much better.
Hi,
I'm developing a data processing pipeline with multiple stages, with data being moved between the stages using shared memory segments. The size of the data is typically of the order of hundreds of megabytes, and there are typically a few tens of main shared memory segments each of size... (2 Replies)
Hi,
I'm trying to figure out the best solution to the following problem, and I'm not
yet that much experienced like you. :-)
Basically I have to read a fairly large file, composed of "messages" , in order
to display all of them through an user interface (made with QT).
The messages that... (3 Replies)
We just set up a system to use large pages. I want to know if there is a command to see how much of the memory is being used for large pages. For example if we have a system with 8GB of RAm assigned and it has been set to use 4GB for large pages is there a command to show that 4GB of the *GB is... (1 Reply)
Hi,
I have one file in this format
20 value1
33 value2
56 value3
I have another file in this format:
34,30-SEP-09,57,100237775,33614510126,2,34
34,30-SEP-09,57,100237775,33620766654,2,34
34,30-SEP-09,108,100237775,33628458122,2,34
34,30-SEP-09,130,100237775,33635266741,2,254... (6 Replies)
Hi Everyone,
#!/usr/bin/perl
use strict;
use warnings;
my @test=("a;b;qqq;c;d","a;b;ggg;c;d","a;b;qqq;c;d");
would like to split the @test array into two array:
@test1=(("a;b;qqq;c;d","a;b;qqq;c;d"); and @test2=("a;b;ggg;c;d");
means search for 3rd filed.
Thanks
find the... (0 Replies)
Hello
I have the following files
VOICE_hhhh
SUBSCR_llll
DEL_kkkk
Consider that there are 1000 VOICE files+1000 SUBSCR files+1000DEL files
When i try to tar these files using
tar -cvf backup.tar VOICE* SUBSCR* DEL*
i get the error:
ksh: /usr/bin/tar: arg list too long
How can i... (9 Replies)
Hi,
I have table in sql ..from this table im storing the first coloumn values in shell array variable ...
after this passing this variable as an arugument in SQL procedure.
But the proc. is running fine only for 1024 values in array ...
How to store more than 1024 values in the array... (5 Replies)
Hi folks,
Sorry for something I'm sure was answered already, I just could not find it in a search of the forums.
I am trying to build a script that eats a config file as:
cat file.cnf | ConProcess.shWhat I want to do inside the script is:
!#/usr/bin/bash
# captured piped cat into an... (6 Replies)
Hi,
I have a file called "readfile" it contains below parameters
#cat readfile
word=/abc=225,/abc/cba=150 three=12 four=45 five=/xyz/yza
likewise multiple line.
From the above file, I have to read "word"
output should be like,
/abc
/abc/cba
these values need to be put in... (3 Replies)
I have nginx web server logs with all requests that were made and I'm filtering them by date and time.
Each line has the following structure:
127.0.0.1 - xyz.com GET 123.ts HTTP/1.1 (200) 0.000 s 3182 CoreMedia/1.0.0.15F79 (iPhone; U; CPU OS 11_4 like Mac OS X; pt_br)
These text files are... (21 Replies)
Discussion started by: brenoasrm
21 Replies
LEARN ABOUT DEBIAN
shell-quote
SHELL-QUOTE(1p) User Contributed Perl Documentation SHELL-QUOTE(1p)NAME
shell-quote - quote arguments for safe use, unmodified in a shell command
SYNOPSIS
shell-quote [switch]... arg...
DESCRIPTION
shell-quote lets you pass arbitrary strings through the shell so that they won't be changed by the shell. This lets you process commands
or files with embedded white space or shell globbing characters safely. Here are a few examples.
EXAMPLES
ssh preserving args
When running a remote command with ssh, ssh doesn't preserve the separate arguments it receives. It just joins them with spaces and
passes them to "$SHELL -c". This doesn't work as intended:
ssh host touch 'hi there' # fails
It creates 2 files, hi and there. Instead, do this:
cmd=`shell-quote touch 'hi there'`
ssh host "$cmd"
This gives you just 1 file, hi there.
process find output
It's not ordinarily possible to process an arbitrary list of files output by find with a shell script. Anything you put in $IFS to
split up the output could legitimately be in a file's name. Here's how you can do it using shell-quote:
eval set -- `find -type f -print0 | xargs -0 shell-quote --`
debug shell scripts
shell-quote is better than echo for debugging shell scripts.
debug() {
[ -z "$debug" ] || shell-quote "debug:" "$@"
}
With echo you can't tell the difference between "debug 'foo bar'" and "debug foo bar", but with shell-quote you can.
save a command for later
shell-quote can be used to build up a shell command to run later. Say you want the user to be able to give you switches for a command
you're going to run. If you don't want the switches to be re-evaluated by the shell (which is usually a good idea, else there are
things the user can't pass through), you can do something like this:
user_switches=
while [ $# != 0 ]
do
case x$1 in
x--pass-through)
[ $# -gt 1 ] || die "need an argument for $1"
user_switches="$user_switches "`shell-quote -- "$2"`
shift;;
# process other switches
esac
shift
done
# later
eval "shell-quote some-command $user_switches my args"
OPTIONS --debug
Turn debugging on.
--help
Show the usage message and die.
--version
Show the version number and exit.
AVAILABILITY
The code is licensed under the GNU GPL. Check http://www.argon.org/~roderick/ or CPAN for updated versions.
AUTHOR
Roderick Schertler <roderick@argon.org>
perl v5.8.4 2005-05-03 SHELL-QUOTE(1p)